Container caps and methods for making them



June 28, 1960 E. J. TOWNS 2,942,747

CONTAINER CAPS AND METHODS FOR MAKING THEM Filed Nov. 22, 1957 2Sheets-Sheet 1 I N VEN TOR. EDI 164 ED 77 Tan/A45 E. J. TOWNS June 28,1960 CONTAINER CAPS AND METHODS FOR MAKING THEM Filed NOV. 22, 1957 2Sheets-Sheet 2 V r 11: i s g 5 7 W 6 5 Z 1 Z 2 Ma 9 0% Z 1 United StatesPatent CONTAINER-CAPS AND METHODS FOR MAKING THEM Edward J. Towns,Livingston, NJ., assignor' to Minne= sota Mining and ManufacturingCompany, St. Paul, Minn., a corporation of Delaware Filed Nov. 22, 1957,Ser. No. 698,082

7 Claims. (Cl. 215-46) This invention relates generally to a cap forsealing a container, such as a bottle, and in one of its more specificaspects to a cap which is adapted to provide an elTective original sealfor a bottle and which is adapted to be readily reused, subsequent toinitial use, to adequately reseal the bottle. This invention alsopertains to an improved method for manufacturing resilient and reusablebottle caps.

A primary object of the invention is to provide a reusable bottle caphaving improved features of construction and design.

Another object of the invention is to provide a bottle cap which isadapted (ti) to be readily applied to a bottle or the like and serve asan effective original seal therefor, (b) to be easily removed from .thebottle, as required, and (c) to be readily and quickly reapplied to thebottle to thereby adequately reseal the same.

The invention has for another object the provision of a reusable bottlecap which indicates visually, whenin active use, whether it is beingused to effect original sealing or resealing of the bottle.

A further object of the invention is to provide a bottle cap of thecharacter indicated that is'simple and attractive in design, that isdurable in construction, that is reasonable in manufacturing cost andthat is capable of performing its intended functions in a satisfactoryand trouble-free manner.

To the end that the foregoing objectives may be attained, a bottle capaccording to this invention is unitary in construction and is made of asuitable resinous composition which may be thermoplastic and/orthermosetting material which is readily moldable and which has theproperties of being flexible, resilient, tearable, and inert andimpervious to moisture and common gases. While polyethylene ispreferred, it is to be understood that other thermoplastic orthermosetting materials having similar properties and characteristicsmay be used in place thereof.

The cap comprises a top wall and outer and inner tubular walls dependingfrom the top wall and open at their lower ends. The inner wall is spacedfrom and substantially coaxial with the outer wall. An annular bead isprovided atthe lower end of the outer wall and projects inwardlythereof. This bead has a plurality of circumferentially spaced blindrecesses that extend upwardly from its lower surface. The recessesextend into the outer wall but terminate inwardly of both the inner andouter surfaces of the outer wall. The recesses may be of any desiredform and, the parts of the cap defining the recesses constitute weakenedareas that are tearable in the course of removing the cap from a bottleby means of a bottle opener or similar device.

The cap is adapted to be readily placed on a bottle and form aneffective seal therewith as will be explained further along herein. Whenthe cap is used to provide an original seal for the bottle, the partsareso arranged that the recesses are not visible and the outer wall iscontinuous and uninterrupted by slits, tears, or the like.

Patented June 28, 1961) At the time the cap is removed from the bottlethe outer wall is partially torn in the region of one or two of therecesses. The cap may-be reused to reseal the bottle by repositioning itthereon. When the cap is used as a resealer, the tears appearing in theouter wall serve as visible indications that the cap is not an originalsealer, but is being used for resealing purposes.

I find that for best results the inner tubular wall of the cap should bepreferably somewhat softer and more pliable than the outer tubular wall.Accordingly, it is recommended that different thermoplastic and/ orthermoset compositions be used for the outer and inner walls. Ifdesired, the cap may be made of two polyethylene compositions havingrequisite characteristics, which are molded to obtain a unitary orone-piece cap construction as will be described further along in thisdescription.

The enumerated objects and other objects, together with the advantagesof this invention, will be readily understood by persons skilled in theart from the following detailed description taken in conjunction withthe accompanying drawings.

In the drawings:

Fig. 1 is a perspective 'view of a cap con'structed'in accordance withthis invention operatively mounted-ona bottle;

Fig. 2 is a central vertical cross-sectional view through the cap andbottle assembly shown in Fig. l;

Fig. 3 is a bottom plan view of the cap showniri a Fig. 4 is an enlargedfragmentary view of a portion of Fig. 3; i

Fig. 5 is an enlarged view of the left hand portion of only the cap ofFig. 2;

Fig. 6 corresponds to Fig. 1 and illustrates the cap in the course ofits being removed from the bottle with the aid of a bottle opener;

Fig. 7 also correspondsto Fig. land depicts the appearance of the capwhen it is being reused for the purpose of resealing the bottle; 7

Fig. 8 is an enlarged central vertical cross sectional view through thecap shown in other views and illustrates the parts thereof that aremolded from one composition and the parts that are molded from a secondcomposition in accordance with this invention;

Fig. 9 is a view in vertical cross section of an arrangement of moldingapparatus for forming certain parts of the cap of this invention;

Fig. 10 is similar to Fig. 9 and illustrates molding apparatus forforming the remaining parts of the cap; and

Fig. 11 is a perspective view of a separating plate.

Reference is now had to the drawings wherein like reference charactersdenote corresponding parts throughout the several views. There isillustrated in Figs. 1 and 2 the upper portion of a bottle B and a cap Cof this invention positioned on and forming a seal with the bottle.

Bottle B is preferably made of glass and may be of any conventionalconstruction and .design that is com monly used to store gas-containingliquids, such as ginger ale, carbonated water and the like. The bottle,to the extent that it is illustrated, includes a tubular neck 10 havingan inner surface 11 and terminating in a pair of outer annular beads,namely an upper bead 12 and a lower bead 13. These beads merge anddefine an annular groove 14, as best shown in Fig. 2.

Cap C comprises a circular top wall 15, a depending outer tubular wallor skirt 16 and a depending inner tubular wall or sealing ring 17 thatis spaced from and coaxial with the outer wall. Walls 15, 16, and 17 areimperforate. Top wall 15 carries a plurality of radial stifiening ribs18 that are positioned wholly within inner wall 17. The lower end ofwall 16 includes an inwardly ethylene composition.

projecting annular head 19. plurality of circumferentially spaced blindrecesses 20 extend into wall 16 as shown in Figs. 4 and 5, but terminateinwardly of the upper inner surface of bead 19. The .parts which define7 individual -20 constitute weakened ae ions of the 61gb. -I-f desired,there an pdsitfoned'on the ribs 18 a fttle'c'ap linerltnot shown)of'aiiy'of the types known 'tbthe'a'r't. I

en g 'a C is ori inally a plied to bottle B, it is Hela ed sufii'ientlyto "soften lits p'arts and .pern1it. pos ition- -n the bottle as shownin Fig. 2, with inner wall 17 disposedin the bottle and forming intimatecontact with J t tle surface 11 and bead 1 9 engaging outer bead 13 o fthe-bottle as :shown. 7 {Eris-is -accomplished without tearing orotherwise breaking through outer wall 16 or bead 19. j V M p I 1Assuming that the bottle contains a carbonated liquid, the fluidpressure within the bottle acts 'on top wall 15 and inner wall 17 a"manner to obtain an effective seal betweeirthe bottle andthe cap. Thebottle and its contents may now be transported, stored or displayedunder normally encountered temperature and pressure conditions without'distupbing the seal. The fact that top wall 15 and outer wall 16 arej'continuous and-uninter rupted by tears or other disfigura'tions servesas a visible indication to a purchaser that the bottle is under itsoriginal seat. In other words, the customer is assured "that theoriginal "seal has not been broken and that the I.

. original contents a-re'intact.

The cap may be readily removed frprn -t hc bottle by includes a handle21, an upper jaw 22 and a lower jaw The opener isadapted to engage the.cap withits upper jaw bearing on top wall 15 and its lower jaw hookedainder outerl-wall m and engaging bead --1-9. The opener is tiltedupwardly in the usual mahner to .prythe cap from the bottle. in thecourse of suchfprying, the

. ni'eans of'a conventional bottle=opener 0 (Fig. 6)f which 7 4 shown inFig. 9, the ends of the slot 3:5 communicate with narrow cylindricalopenings 9 which in turn communicate with annular groove 8 in'registrywith groove 23. A polyethylene or other resinous composition ofpredetermined desirable properties is injected by the use of pressureand heat through 'the central opening in the tube 3%), into and throughthe confined slot 35, into and thrbu-gh the pair of narrowe ilindficalopenings 9 and into the mold space *d'e'fined by tlie grooves 8 and 28to thereby form the annular inner wall 17 together with an annular 11112 7 1-7 a integral themwi-th and -have a pair of space annular beads475-011the-llppelfifafie therwf Block 31 is adapted to be replaced by asimilar block 37 for the purpose "offforining "top wail pants, ribs 18,outer wall16 and bead d9. As shownin Fig. 10, block 37 and mold 27define a space 33 corresponding in size and configuration to outer wall16. Block' 32 is likewise replaced by a similar block 32a and spacedabove the earlier formed portions of the cap, as indicated at 39. Thisconstruction permits ready injection ofa second polyethylene or otherresinous composition 4%) (Fig. 8) of the desired characteristics intothe 'mold spaces to form top wall part'1 5,-ribs 18, outer wall 16together with its bead 1 9. The composition is in "a molten orsemi-molten state during molding, whereby fusion occurs betweencomposition 40 and ring 17a so that wa1l-17 and top wall 1 5 are bondedtogether to obtain a unitary cap. 7 I 'Recess es 20 aretpreferablyformedrinthe lower end 'of outer wall :16 "after molding iscompletediand the "cap is removed from the molding apparatus. Itwillbe-apa preciated that the reces'ses may be formed during themoldingprocedurqif desired.

opener" causes partial {tearing of -outer 'wall 16"and bead 19 in theregions of recesses 20 that -are-adjacent jaw 23,

j as shown in Fig. 6. Typical tear lines resulting from use ofthe-opener areindicated-by-numeral 24 in Figs. 6 and 7.-

Despite the tears resulting from breaking the original seal, the eap may-be repeatedly reused to :f'reseal-th'e contents of the bottle or otherbottles. Tearlines 24cm:-

' stitute an indication to a user that the cap is being-used forrescaling purposes as distinguished from original sealing. t

{As was "mentioned earlier in this description, inner tubular wall'17 ispreferably made ofia thermoplastic t composition that 'is somewhatsofter, mor'e lpliable and thereforenflore flexible -than=outer tubularwall16. {Fig 8 illustrates a cap that is formed from two polyethylenecom ositions to obtain a'c'onstru'ctionhavin'g the indicated propertiesand characteristics. -ln,-Fig. '8, inner wall =17 i's first tor-med fromthe softeri'p'olyethylene-composition while -outer wall 16, annular bead1-9, the top wall :15

From'the foregoing, it is believed that construction-and advantages ofthe bottle cap of this invention and the method of making the same willbe readily comprehended by spers on'sskilled in -the art, withoutfurther description. It is to be understood, howver that theinventionisnot to be limited to the exact details -describedand-shown hereinjbut isto be accorded the full scope and protection of theappende'd claims.

Iclaimz. V V

1. In a frangible cap whi6h= -is adapted to seal a container, such as abottle, having an outer beadf at its discharge end, a top wall, an outertubular'wall depending iron; the top wall "and open at its lower end aninner tubular wall depending from the top'wall and open at its lowerend,said inner wall being spaced -from and substantially coaxialwiththeo'uter 'wall 'the lo wer end of the outer wall including arrinwardlyextending annular bead,-said lower end having fofmed thereina pluirality of circumterent'ially-spaeedblind recesses that exribs 18 are allmade of a stiffen-less pliable poly-' I Reference is next had to Figs.'9 and =10' which illustrate molding apparatus for forming-the cap of-Fig. V molding apparatus includes a. press comprising 'a lower-platen25 which c'arries a-bed:plate 26. Mounted on the bed'zplate' is a mold-27 having a plurality of -'g'rooy es,-namely an annular -to'p groovezficorresponding ingsize and' config'uration'to inner wall-17,--a1plurality of 'radial top grooves -29 corresponding "inriufiiben-size and configuration to ribs 18, and *an annular-side groove 3t!corresponding in size-and configuration to head 19.

saidgplzitegand communicatingat its central ;part with :tube;33..iWith-the ip'arts' disposed in the-relationship as tend upwardlytromjits lower surfaee,isaid cap "being 7 adaptedto be operativelyiconnected to the bottle with the top wall positioned over and acrossthe'disch'arge end of'the bottle, the inner wall disposed in and formingintimate contact with the inner surface "of the discharge end of thebottle, the outer walleiicircling-thebottle outer bead and the annularbead forming;-continuous intimate contact with the bottle outer bead,the parts ojfthe cap which define the {recesses constituting relativelyweak regions-that areadapted to be'torn'in thecourse offpryin'g the capiromlhe bottle.

' :2- ln a iralngible cap whieh isadapted to sealla con- 7 7 tainer,such as a bottle, havingian outer'bead 'at its dischargeend, atopewallyanlouter tubular jwall depending 'fromthe top' wall and openatits lower end. :an inner tubular walldepending -fr' om' .thetop Wellandopen at its lower end, said :irinefWllbeingQSpa'ddTrent and 7 andinnerwalls-being imperforate, thedower end of the.

substantially-coaxial withihe-outr wan, said top,.6uter outerwallincludingan inwardlyrprojecting annularlbead,

. said lower 7 end having formed therein alplurality ofcircumferentially spacedblindtrecesses that 'extendupwar'dly from itslower :surfacie, s'aid caip being adapted to be operatively connected tothe bottle with the top wall positioned over and across the dischargeend of the bottle, the inner wall disposed in and forming intimatecontact with the inner surface of the discharge end of the bottle, theouter wall encircling the bottle outer bead and the inwardly projectingbead forming continuous intimate contact with the bottle outer bead, theparts of the cap which define the recesses constituting relatively weakregions that are adapted to be torn in the course of prying the cap fromthe bottle.

3. In a frangible cap which is adapted to seal a can tainer, such as abottle, having an outer bead at its discharge end, a top wall, an outertubular wall depending from the top wall and open at its lower end, aninner tubular wall depending from the top wall and open at its lowerend, said inner wall being spaced from and substantially coaxial withthe outer wall, the lower end of the outer wall including an inwardlyprojecting annular head, said lower end having formed therein aplurality of circumferentially spaced blind recesses that extendupwardly from its lower surface, that extend into the outer wall andthat terminate inwardly of the outer surface of the outer wall, said capbeing adapted to be operatively connected to the bottle with the topwall positioned over and across the discharge end of the bottle, theinner wall disposed in and forming intimate contact with the innersurface of the discharge end of the bottle, the outer wall encirclingthe bottle outer bead and the inwardly projecting bead formingcontinuous intimate contact with the bottle outer bead, the parts of thecap which define the recesses constituting relatively weak regions thatare adapted to be torn in the course of prying the cap from the bottle.

4. In a frangible cap which is adapted to seal a container, such as abottle, having an outer head at its discharge end, a top wall, an outertubular wall depending from the top wall and open at its lower end, aninner tubular wall depending from the top wall and open at its lowerend, said inner wall being spaced from and substantially coaxial withthe outer wall, said top, outer and inner walls being imperforate, thelower end of the outer wall including an inwardly projecting annularhead, said lower end having formed therein a plurality ofcircumferentially spaced blind recesses that extend upwardly from itslower surface, that extend into the outer wall and that terminateinwardly of the outer surface of the outer wall, said cap being adaptedto be operatively connected to the bottle with the top wall positionedover and across the discharge end of the bottle, the inner wall disposedin and forming intimate contact with the inner surface of the dischargeend of the bottle, the outer wall encircling the bottle outer bead andthe annular bead forming continuous intimate contact with the bottleouter head, the parts of the cap which define the recesses constitutingrelatively weak regions that are adapted to be torn in the course ofprying the cap from the bottle.

5. In a frangible cap which is adapted to seal a container, such as abottle, having an outer bead at its discharge end, a top wall, an outertubular wall depending from the top wall and open at its lower end, aninner tubular wall depending from the top wall and open at its lowerend, said inner wall being spaced from and substantially coaxial withthe outer wall, a plurality of stiffening ribs depending from the topwall and positioned wholly within the inner wall, the lower end of theouter wall including an inwardly extending annular bead, said lower endhaving formed therein a plurality of circumferentially spaced blindrecesses that extend upwardly from its lower surface, said cap beingadapted to be operatively connected to the bottle with the top wallpositioned over and across the discharge end of the bottle, the innerwall disposed in and forming intimate contact with the inner surface ofthe discharge end of the bottle, the outer wall encircling the bottleouter bead and the annular bead forming continuous intimate contact withthe bottle outer bead, the parts of the cap which define the recessesconstituting relatively weak regions that are adapted to be torn in thecourse of prying the cap from the bottle.

6. In a frangible cap which is adapted to seal a con tainer, such as abottle, having an outer head at its discharge end, a top wall, an outertubular Wall depending from the top wall and open at its lower end, aninner tubular wall depending from the top wall and open at its lowerend, said inner wall being spaced from and substantially coaxial withthe outer wall, said top, outer and inner walls being imperforate, aplurality of stilfening ribs depending from the top wall and positionedwholly within the inner wall, the lower end of the outer well includingan inwardly projecting annular head, said lower end having formedtherein a plurality of circumferentially spaced blind recesses thatextend upwardly from its lower surface, that extend into the outer walland that terminate inwardly of the outer surface of the outer wall, saidcap being adapted to be operatively connected to the bottle with the topwall positioned over and across the discharge end of the bottle, theinner wall disposed in and forming intimate contact with the innersurface of the discharge end of the bottle, the outer wall encirclingthe bottle outer bead and the annular bead forming continuous intimatecontact with the bottle outer bead, the parts of the cap which definethe recesses constituting relatively weak regions that are adapted to betorn in the course of prying the cap from the bottle.

7. in a one-piece thermoplastic, flexible, frangible cap which isadapted to seal a container, such as a bottle, having an outer bead atits discharge end, a top wall, an outer tubular Wall depending from thetop wall and open at its lower end, an inner tubular wall depending fromthe top wall and open at its lower end, said inner wall comprising amaterial that is more pliable than the material of the outer wall andbeing spaced from and substantially coaxial with the outer wall, saidtop, outer and inner walls being imperforate, a plurality of stiffeningribs, depending from the top wall and positioned wholly within the innerwall, the lower end of the outer well including an inwardly projectingannular head, said lower end having formed therein a plurality ofcircumferentially spaced blind recesses that extend upwardly from itslower surface, that extend into the outer wall and that terminateinwardly of the outer surface of the outer well, said cap being adaptedto be operatively connected to the bottle with the top well positionedover and across the discharge end of the bottle, the inner wall disposedin and forming intimate contact with the inner surface of the dischargeend of the bottle, the outer wall encircling the bottle outer bead andthe annular bead forming continuous intimate contact with the bottleouter bead, the parts of the cap which define the recesses constitutingrelatively weak regions that are adapted to be torn in the course ofprying the cap from the bottle.

References Cited in the file of this patent UNiT ED STATES PATENTSWoydatt et al. Dec. 4, 1956

